Support and cover structures for an ultrasound probe head

ABSTRACT

A probe cap for use with an ultrasound probe including a head portion and an acoustic surface is disclosed. In one embodiment, the probe cap includes a body that defines a cavity sized for releasably receiving the head portion of the probe therein. The probe cap body further defines a hole that is proximate the acoustic surface of the head portion. A compliant spacer component is disposed in the hole. The spacer component can include a hydrogel and provides an acoustic path between the acoustic surface and a tissue surface of a patient. The spacer component includes a skin contact surface that defines a concavity and is deformable against the tissue surface. Additional embodiments disclose various probe cap and accompanying needle guide designs for use in assisting a clinician with ultrasound probe use and needle insertion into a patient.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. application Ser. No.12/900,750, filed Oct. 8, 2010, and entitled “Spacers for Use with anUltrasound Probe,” which claims the benefit of U.S. Provisional PatentApplication No. 61/372,044, filed Aug. 9, 2010, and entitled “Supportand Cover Structures for an Ultrasound Probe Head,” and of U.S.Provisional Patent Application No. 61/249,850, filed Oct. 8, 2009, andentitled “Ultrasound Probe Spacers.” Each of these applications isincorporated herein by reference in its entirety.

BRIEF SUMMARY

Briefly summarized, embodiments of the present invention are directed toa probe cap for use with an ultrasound probe including a head portionand an acoustic surface. In one embodiment, the probe cap includes abody that defines a cavity sized for releasably receiving the headportion of the probe therein. The probe cap body further defines a holethat is proximate the acoustic surface of the head portion. A compliantspacer component is disposed in the hole. The spacer component caninclude a hydrogel and provides an acoustic path between the acousticsurface and a tissue surface of a patient. The spacer component furtherincludes a skin contact surface that defines a concavity and isdeformable against the skin. The skin contact surface can further defineone or more spacer elements adjacent the concavity for distributing theload of the probe pressing against the skin and preventing compressionof subcutaneous structures of the patient.

In another embodiment, an ultrasound imaging system for imaging asubcutaneous structure of a patient is disclosed and includes a display,an ultrasound probe including an acoustic surface from which ultrasoundsignals are emitted, and first and second spacer elements. The spacerelements are positioned proximate opposite ends of the acoustic surfaceand are configured to provide a gap between the acoustic surface and atissue surface of the patient. So configured, the spacer elementsprevent compression of the subcutaneous structure of the patient.

In addition, embodiments to be further described below disclose variousprobe cap and accompanying needle guide designs for use in assisting aclinician with ultrasound probe use and needle insertion into a patient.

These and other features of embodiments of the present invention willbecome more fully apparent from the following description and appendedclaims, or may be learned by the practice of embodiments of theinvention as set forth hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

A more particular description of the present disclosure will be renderedby reference to specific embodiments thereof that are illustrated in theappended drawings. It is appreciated that these drawings depict onlytypical embodiments of the invention and are therefore not to beconsidered limiting of its scope. Example embodiments of the inventionwill be described and explained with additional specificity and detailthrough the use of the accompanying drawings in which:

FIGS. 1A and 1B are perspective and side views, respectively, of anultrasound probe including spacer elements configured in accordance withone embodiment;

FIG. 2 is a simplified cross sectional view of the ultrasound probe ofFIGS. 1A and 1B used to image a vessel of a patient;

FIG. 3 is a side view of the ultrasound probe of FIGS. 1A and 1Benclosed within a sheath in accordance with one embodiment;

FIGS. 4A and 4B are side views of a portion of an ultrasound probeincluding spacer elements and further showing examples of possibleacoustic surface configurations in accordance with one embodiment;

FIG. 5 is a side view of a portion of an ultrasound probe including aspacer element in accordance with one embodiment;

FIG. 6 shows ultrasound spacer elements configured in accordance withone embodiment;

FIG. 7 shows ultrasound spacer elements configured in accordance withone embodiment;

FIG. 8 shows ultrasound spacer elements configured in accordance withone embodiment;

FIGS. 9A and 9B show spacer elements configured in accordance with oneembodiment;

FIG. 10 is a side view of an ultrasound probe including spacer elementsconfigured in accordance with one embodiment;

FIG. 11 is a side view of an ultrasound probe including a cap includingspacer elements and a sheath in accordance with one embodiment;

FIG. 12 is a perspective view of a spacer component in accordance withone embodiment;

FIGS. 13A-13C show use of the spacer component of FIG. 12 in accordancewith one embodiment;

FIG. 14 is a side view of a spacer component in accordance with oneembodiment;

FIGS. 15A-15B show use of the spacer component of FIG. 14 in accordancewith one embodiment;

FIG. 16 is an exploded perspective view of an ultrasound probe and aprobe cap in accordance with one embodiment;

FIGS. 17A-17D are various views of the probe cap of FIG. 16;

FIGS. 18A and 18B are an exploded perspective view and cross sectionalside view of an ultrasound probe/probe cap and a spacer component,respectively;

FIG. 19 is a cross sectional view of a head portion of the ultrasoundprobe of FIG. 16;

FIG. 20 is a cross sectional view of the probe cap of FIG. 16;

FIG. 21 is a cross sectional view of a head portion of the ultrasoundprobe of FIG. 16 received within the probe cap of FIG. 16;

FIG. 22 is another cross sectional view showing a head portion of theultrasound probe of FIG. 16 received within the probe cap of FIG. 16;

FIG. 23 is a perspective view of a mated configuration of the ultrasoundprobe and probe cap of FIG. 16;

FIGS. 24A and 24B are front and side views, respectively, of anultrasound probe and accompanying probe cap including a compliant spacercomponent according to one embodiment;

FIG. 24C is a perspective view of the probe cap of FIGS. 24A and 24B;

FIGS. 25A-25D are various views of a probe cap according to oneembodiment;

FIGS. 26A and 26B are various exploded views of a probe cap configuredaccording to one embodiment;

FIG. 27 is a side view of the probe cap of FIGS. 26A and 26B shown incontact with a patient's skin above a subcutaneous vessel;

FIGS. 28A and 28B are perspective and cross sectional views,respectively, of a probe cap according to one embodiment;

FIGS. 29A-29D are various views of a probe cap assembly according to oneembodiment;

FIGS. 30A and 30B are various perspective views of a probe cap accordingto one embodiment;

FIG. 31 is a cross sectional side view of the probe cap of FIGS. 30A and30B shown attached to an ultrasound probe;

FIG. 32 is a perspective view of a probe cap according to oneembodiment;

FIGS. 33A and 33B are partial cross sectional side views of anultrasound probe and probe cap in accordance with one embodiment;

FIG. 34 is a perspective view of a needle guide according to oneembodiment; and

FIGS. 35A and 35B are side and perspective views, respectively, of theneedle guide of FIG. 34 attached to a probe cap according to oneembodiment.

DETAILED DESCRIPTION OF SELECTED EMBODIMENTS

Reference will now be made to figures wherein like structures will beprovided with like reference designations. It is understood that thedrawings are diagrammatic and schematic representations of exemplaryembodiments of the present invention, and are neither limiting nornecessarily drawn to scale.

For clarity it is to be understood that the word “proximal” refers to adirection relatively closer to a clinician using the device to bedescribed herein, while the word “distal” refers to a directionrelatively further from the clinician. For example, the end of acatheter placed within the body of a patient is considered a distal endof the catheter, while the catheter end remaining outside the body is aproximal end of the catheter. Also, the words “including,” “has,” and“having,” as used herein, including the claims, shall have the samemeaning as the word “comprising.”

Embodiments of the present invention are generally directed to variouscomponents for spacing an acoustic surface of an ultrasound probe from atissue surface of a patient during ultrasound procedures to imagesubcutaneous tissues of the patient. Such ultrasound procedures areemployed, for instance, in connection with the placement of a catheterwithin a vessel of the patient. As will be described, the components forspacing the acoustic surface in one embodiment prevent undesiredcompression of subcutaneous vessels, especially superficial vessels,which in turn improves the imaging of such vessels by the probe. Inaddition, embodiments to be described further below disclose variousprobe cap and accompanying needle guide designs for use in assisting aclinician with ultrasound probe use and needle insertion into a patient.

Reference is first made to FIGS. 1A and 1B, which depict an ultrasoundimaging system 10 according to one embodiment, including an ultrasoundprobe 12 and a console 20 including a display 30 for depicting an imageproduced by the probe. In the present embodiment, the probe 12 isoperably connected to the console 20 via a cable 31, though in oneembodiment the probe can be wirelessly connected thereto.

The probe 12 includes a head 32 defined by a longitudinal length 32A anda width 32B. The body of the probe generally defines a front face 33A, arear face 33B, and side faces 33C. It should be appreciated that thepreceding description of the probe is not meant to limit application ofthe principles described herein in any way. The probe head 32 includesan acoustic surface 34 extending along at least a portion of alongitudinal length 32A of the probe head from which ultrasonic impulsesare emitted in order to penetrate and image subcutaneous portions of thepatient. Note that the size, shape and configuration of both the probeand acoustic surface can vary from what is described herein while stillresiding within the principles of the present disclosure. Note also thatFIG. 1A shows just one example of an ultrasound imaging system; othersystems including other components can also benefit from the principlesdescribed herein.

As depicted in FIGS. 1A and 1B, in accordance with one embodiment theprobe head 32 includes two spacer elements, generally depicted at 40,disposed adjacent the probe acoustic surface 34 at each end of thelongitudinal length 32A. Each spacer element 40 acts as an extendedsurface to provide a gap 48 between the acoustic surface 34 and the skin36 or other tissue surface of the patient, as further described below,when the probe 12 is placed on the patient's skin for use insubcutaneous imaging.

In greater detail, each spacer element 40 in the present embodimentdefines a blade-like extended surface that includes a contact surface 42for contacting the tissue/skin 36 of the patient. The contact surface 42can be shaped in one of several configurations, as will be discussedfurther below.

Reference is now made to FIG. 2. When no spacers are present on anultrasound probe, the acoustic surface thereof directly contacts thepatient's skin during imaging, which can cause a downward pressuresufficient to undesirably compress a subcutaneous vessel disposedbeneath the probe. Further, the proximity of the probe acoustic surfaceto the patient's skin can cause the focal point of the probe to residebelow the vessel to be imaged, resulting in less than optimal imageresolution of superficial vessels or other objects residing relativelyclose to the skin surface.

In contrast to the above, FIG. 2 shows the probe 12 including the spacerelements 40 disposed at each longitudinal end of the probe head 32 andadjacent the acoustic surface 34. So configured, the acoustic surface 34is spaced apart from the patient's skin 36 during probe use, and onlythe contact surfaces 42 of the spacer elements 40 are in contacttherewith. The gap 48 is thus defined between the acoustic surface 34and the patient's skin 36, which can be filled with an ultrasonic gel 84or other acoustically transparent substance to improve imaging, in oneembodiment.

Because the acoustic surface 34 of the ultrasound probe head 32 is notin direct contact with the patient's skin 36 during probe use, pressureon the skin imposed by the acoustic surface is avoided, which in turnprevents a vessel 50 underneath the probe 12 from being compressed bythe probe during use. Instead, any downward force provided by the probe12 is directed through the spacer elements 40. As such, the vessel 50below the acoustic surface 34 remains patent and can be accuratelyimaged. Further, the increased distance between the acoustic surface 34and the patient's skin 36 provided by the gap 48 moves the focal spot ofthe probe 12 to a location relatively close below the skin surface,which enables superficial vessels and other objects residing near theskin surface to be brought more closely to the focal point of the probeand be sharply imaged.

Note that the gap 48 shown in FIGS. 1A-2 is bounded during probe use bythe acoustic surface 34, the skin 36, and the spacer elements 40. Assuch, the gap 48 remains open below the front and rear faces 33A, 33B ofthe probe 12. Note that additional spacers could be employed to furtherdefine the gap 48, if desired.

Reference is now made to FIG. 3 in describing one embodiment, wherein asheath 52 is placed over the probe 12 to provide a sterile field aboutthe probe. The sheath 52 can be disposed about the probe 12 such that arelatively close fit is defined between the sheath and the side faces33C and front/rear faces 33A, 33B of the probe so that the ultrasoundgel 84 can be included in and confined within the gap 48 by the sheathand the spacer elements 40. Note that sheaths or barriers of manydifferent styles or configurations may be used.

FIGS. 4A and 4B show example surface configurations for the acousticsurface 34. In FIG. 4A, the acoustic surface 34 is flat as to besubstantially parallel with the patient's skin 36 during probe use. InFIG. 4B, the acoustic surface 34 defines a concave shape with respect tothe skin 36. This configuration can assist in trapping a volume ofultrasound gel within the gap 48. Of course, other acoustic surfaceconfigurations can be employed.

FIG. 5 gives one example of a possible configuration for the contactsurface 42 of the spacer element 40, wherein the contact surface definesa convex shape for engagement with the patient's skin or other tissuesurface. Note this is in contrast to the relatively flat contact surface42 shown in FIGS. 4A and 4B, for instance. Other spacer contact surfaceshapes can be employed, including straight, rounded, angled, etc.

FIG. 6 shows that a height “H” of each spacer element 40 can be definedaccording to a particular need or application in order to define aparticular separation between the acoustic surface 34 and the patient'sskin 36 during use of the probe 12. Note that in one embodiment, thespacer elements are integrally formed with the probe housing. In anotherembodiment, the spacer elements are removably attached to the probe. Thespacer elements can include materials similar to or different from thosematerials included in the probe housing.

Reference is now made to FIGS. 7 and 8, wherein FIG. 7 shows that in oneembodiment the spacer elements 40 can be configured to extendlongitudinally a distance “E” past the side surfaces 33C of the probe12. In FIG. 8, each of the spacer elements 40 is inset a distance “I”from the probe side surfaces 33C.

FIGS. 9A and 9B depict yet another possible spacer element configurationaccording to one embodiment, wherein each spacer element 40 is includedat an end of an extension arm 48 that extends from a corresponding oneof the front and rear faces 33A, 33B of the probe 12. Such aconfiguration may be useful, for instance, in advancing the probe 12along the patient skin 36 in a direction parallel to the longitudinallength of the acoustic surface 34. These and other spacer configurationsare therefore contemplated as residing with the spirit of the presentdisclosure.

FIG. 10 shows a height-adjustable spacer element 40 so as to allowvariation in the set-off distance of the acoustic surface 34 from theskin 36. In the illustrated embodiment, a bracket 60 that slidablyreceives the spacer element 40 is included on the side face 33C of theprobe 12 and includes a depression or hole 62. Correspondingprotuberances 64 are included on the spacer element 40 and areconfigured to be selectively received into the hole 62 so as toremovably lock the spacer element in place at a specified height. Theprotuberances 64 are distributed along the length of the spacer element40 such that one of multiple spacer heights may be selected. A similarlyadjustable spacer element is included on the opposite side face of theprobe 12. Of course, other adjustable spacer element configurations canbe included on the probe in addition to that explicitly described here.

FIG. 11 shows details of yet another embodiment, wherein the spacerelements 40 are included on a cap 70 that is removably attachable to theprobe head 32. In the present embodiment, the cap is snapped on to theprobe head 32 via an interference fit, but in other embodiments otherattachment schemes can be employed, including inter-engaging surfaces onthe probe and cap, for example. A sheath 72 is attached to the cap 70 soas to provide a sterile barrier for the ultrasound probe 10. In oneembodiment the cap 70 and sheath 72 are disposable.

It should be appreciated that the number, size, height, shape, etc., ofthe spacer elements can vary from what is explicitly described herein.For instance, one, three, or more spacers can be included. Or therelative heights of the spacers can differ one from another so as toproduce an angled probe-to-skin configuration. The probe can include oneof many different shapes, designs, etc. These and other modificationsare thus considered part of the present disclosure.

FIG. 12 depicts details of a spacer component 78 configured forattachment to the probe head 32, as shown in FIG. 13A, according to oneembodiment. The spacer component 78 includes a body of compliantmaterial, such as a hydrogel, in one embodiment, which generallymaintains its intended shape when deforming forces are absent. Thecompliant material in one embodiment can include AQUAFLEX® ultrasoundgel from Parker Laboratories, Inc., Fairfield, N.J. The spacer component78 further defines spacer elements 80 on each longitudinal end thereof,with a concavity 82 defined between the spacer elements. It isappreciated that other suitable materials can be employed for thecompliant material of the spacer component, including acousticallytransparent, sufficiently solid materials such as soft silicone, rubber,etc. In one embodiment, the compliant material is thermoformable,sterilizable, and shelf stable for at least one year.

As shown in FIGS. 13A-13C, the spacer component 78 due to its compliantnature can deform so as to conform to the shape of the surface of thepatient's skin 36 during use of the probe 12. For example, the probe 12including the spacer component 78 can be placed on a patient's arm. Sopositioned, the spacers 80 of the spacer component 78 can deform asneeded as to match the cross sectional curvature of the arm surface andmaintain contact with the skin 36 thereof. FIGS. 13B and 13C show suchdeformation of the spacer component 78 for relatively larger arms. Thus,the spacer component 78 provides an acoustic path between the acousticsurface and the skin surface without need of a flowable ultrasound gel.It is appreciated that the spacer component can be used in connectionwith imaging other portions of the patient's body and that the spacercomponent can define other shapes for contacting differently shaped bodyportions. Further, in one embodiment, an ultrasound gel can be includedbetween the spacer component and the skin, such as in the concavitythereof.

FIG. 14 depicts a spacer component 90 according to another embodiment,including a flexible casing 92 that can operably attach to the probehead 32, as shown. The casing 92 includes arms 92A that contain acompliant insert 94, such as hydrogel in one embodiment. As shown inFIGS. 15A and 15B, the spacer component 90 is positioned on the probehead 32 so as to provide both spacing and an acoustic path between theacoustic surface 34 and the surface of the skin 36 or other tissuesurface such that flowable ultrasound gel is not needed. So configured,the insert 94 thereof defines a contact surface 96 for contacting thesurface of the skin 36 during ultrasound probe use. In one embodiment,the arms 92A of the casing 92 can be pressed inward to modify the shapeof the contact surface 96. For instance, FIG. 15A shows that the contactsurface 96 of the insert 94 defines a relatively shallow concavity 98when the arms 92A of the casing 92 are allowed to flex outward. When thearms 92A are pressed inward as in FIG. 15B, however, the insert 94 iscompressed by the arms and the concavity 98 of the contact surface 96becomes relatively more pronounced. Such a configuration of the contactsurface 96 may be desirable to stabilize a position of the subcutaneousvessel while preventing its collapse. The arms 92A can be biased torestore themselves to a given position when not being pressed by a user.

FIG. 16 shows details of a probe cap 110 for use with the probe 12according to one embodiment. The cap 110 is configured to receivetherein the head 32 of the probe 12 and to provide a spacer component118 for providing desired spacing between the acoustic surface 34 of theprobe head 32 and the skin 36.

As shown in FIGS. 17A-17D, the cap 110 defines a cavity 112 that issized to receive therein the head 32 of the probe 12. An engagementfeature 114 is included with the cap 110 to releasably and mechanicallyattach the cap to the probe 12, though it is appreciated that variousdesigns can be employed to accomplish the same functionality. The cap110 further includes a needle guide base 116 on which a detachableneedle guide can be placed so as to assist a clinician in placing aneedle through the skin 36 after a vessel has been located through useof the ultrasound system 10 (FIG. 1A).

With continuing reference to FIGS. 17A-17D, reference is made to FIGS.18A and 18B, which depict various details of the spacer component 118,which is disposed in a hole 130 defined in the cap 110, best seen inFIGS. 17A and 17C. As shown, the spacer component 118 includes a skincontact surface 126 that defines two spacer elements 120 and a concavity122 disposed therebetween. The spacer component includes 118 a compliantmaterial, such as hydrogel in one embodiment, though it is appreciatedthat other suitable materials can also be employed. The spacer component118 thus requires no use of flowable ultrasound gel to be applied to theskin 36 in order to provide an acoustic path between the acousticsurface 134 and the patient's skin. The spacer component 118 furtherdefines a lip 128 about a perimeter thereof to assist in its retentionwithin the hole 130 of the cap 110, as seen in FIG. 18B. As shown, inthe present embodiment the lip 128 is shaped so as to be sandwichedbetween the cap 110 and probe head 32, thus preventing its unintendedremoval from the cap. A recess 138 is also shown on the cap 110 toreceive therein an orientation nub 140 on the probe head 32, which nub140 provides a landmark for orienting an ultrasound image on the display30 (FIG. 1A) with the orientation of the probe 12 as held by theclinician.

FIG. 19 shows that in the present embodiment the acoustic surface 134 ofthe probe head 32 defines a convex shape. Correspondingly, FIG. 20 showsthat a probe contact surface 136 of the compliant spacer component 118also defines a convex surface. FIG. 21 shows that when the probe head 32is received into the cavity 112 of the cap 110, the convexly shapedprobe contact surface 136 of the spacer component 118 deformably engagesthe convexly shaped acoustic surface 134 of the probe head 32 so as toensure adequate contact therebetween and to provide a suitable acousticpath through the spacer component. Of course, other complementary shapescan be employed on the acoustic surface and probe contact surface of thespacer component.

FIG. 22 shows another view of the engagement between the probe head 32and the cap 110, according to the present embodiment. FIG. 23 shows thecap 110, including the spacer component 118, removably attached to theprobe 12. Note that in one embodiment the cap provides a sterile barrierfor the probe head, and is disposable.

FIGS. 24A-24C depict the probe cap 110 and the concavely-shaped,compliant spacer component 118 according to one embodiment, togetherwith the ultrasound probe 12. As shown, a suitably shaped cover 148 isalso included for covering the spacer component 118 to preventcontamination thereof and to prevent the spacer component from dryingout before use. When use of the probe cap is desired the cover 148,which is fit to the probe cap 110 via a friction or other suitable fit,can be simply removed and discarded by the clinician.

As best seen in FIG. 24C, the cap 110 includes in the present embodimenta bracket 144 to which a needle guide can be removably attached so as toenable guidance of a needle toward a desired vessel imaged by theultrasound probe 12. Further details regarding one non-limiting exampleof a needle guide that can be attached to the bracket 144 can be found,for instance, in U.S. Provisional Application No. 61/426,297, filed Dec.22, 2010, and entitled “Selectable Angle Needle Guide,” which isincorporated herein by reference in its entirety. Note that the needleguide and bracket can vary from what is shown and described herein.

The discussion below discusses yet other structures for enhancing use ofan ultrasonic probe in connection with placement of catheters and othermedical devices in the body of a patient. Indeed, the embodimentsdisclosed herein facilitate ease of use when ultrasonically imagingportions of the patient body in preparation for device placementtherein. Examples of such placement scenarios include the insertion by aclinician of a needle, PICC catheter, PIV catheter, mid-line catheter,etc. into the patient body via a transcutaneous insertion site.

FIGS. 25A-25D show details of a probe cap 160 according to oneembodiment, which defines a cavity 162 for receiving therein the head 32of the probe 12 and an engagement feature 164 for enabling removableengagement of the cap to the probe head. A fixture 166 is included onthe side of the cap 160 and is configured for removably receivingthereon a needle guide 192. In another embodiment, this and other needleguides disclosed herein can be permanently attached to the cap. Notethat, though not shown here, a spacer component similar to those shownand described in connection with FIGS. 24A-24C is disposed in theaperture 130 of the cap 160 to provide an acoustic pathway from theprobe head 32 to the patient's skin.

As best seen in FIG. 25D, the needle guide 192 defines a channel 194into which a portion of a cannula of a needle to be inserted into thepatient can be temporarily received. Note that the size of the channelcan accommodate needle cannulas of various sizes/diameters, as here, orcan be configured to accept needles of a predetermined size. An abutmentsurface 196 is included at a distal end of the channel 194 about whichthe needle can pivot so as to continuously define differing angles ofattack with respect to the patient's skin during needle insertionprocedures. As such, the needle guide 192 is capable of guiding theneedle at any one of a variety of angles of attack toward the patient'sskin while maintaining alignment of the needle with the subcutaneousvessel being imaged by the probe 12.

Note that the probe cap 160 and other caps discussed herein can beconfigured to mate with the head portion of the ultrasound probe in avariety of ways, including friction fit, clip-pocket engagement,adhesively, hook-and-loop, etc. The cap portion of the probe cap canalso vary in design from what is shown and described herein.

The cap 160 further includes a stabilization arm 200 extending from adistal portion of the cap body. The stabilization arm 200 is configuredto rest against the skin of the patient when the cap-equipped probe isheld vertically and placed against the patient's skin during ultrasoundimaging procedures, thus stabilizing the probe in the vertical position.Moreover, the stabilization arm 200 can assist in securing thecap-equipped probe to the patient's skin via the use of a cord orelastic band, for instance, that is extended about the patient's arm andover the stabilization arm, thus maintaining the ultrasound probe in theupright position without manual contact by the clinician during use andproviding more freedom to the clinician during the imaging procedure. Ahole 202 is also defined in the stabilization arm 200 in one embodimentto enable the clinician to press the patient's skin therethrough inorder to locate/occlude a subcutaneous vessel. The area proximate theperimeter of the hole 202 is contoured in the present embodiment toassist with finger placement by the clinician. FIGS. 26A and 26B showvarious details of a probe cap 210 according to another embodiment,including a cavity 212 defined by the cap body that is configured tosupportably receive the head 32 of the ultrasound probe 12 therein viasnap-fit or other suitable modality. A fixture 216 for receiving thereona needle guide is also included on the cap body.

A compliant membrane 218 defining a lip 218A about its perimeter isincluded for attachment to the cap body. Specifically, the cap bodydefines a ridge 219 about an aperture 230 at the distal end of the body.The lip 218A of the membrane 218 is configured to resiliently attach tothe ridge 219 so as to join the membrane to the cap body and cover theultrasound transducer of the probe head 32 when the cap 210 is attachedto the probe 12. The membrane 218 thus provides an acoustic pathwaybetween the transducer and the patient's skin. Note that ultrasound gelon the patient's skin may, but need not, be used with the cap 210 duringultrasound imaging. Note also that the membrane 218 in one embodimentincludes silicone, though other suitable, compliant materials can alsobe employed.

In greater detail, the ridge 219 includes a concavely shaped concavity222, as best seen in FIGS. 26A and 27, such that it defines twostandoffs, or spacers 220, on either end. The compliant nature of themembrane 218 enables it to deform to the concavity 222 of the ridge 219when the membrane is placed against the patient's skin during ultrasoundprocedures. Thus, the membrane 218 can conform to the skin 36 of thepatient during ultrasound imaging so as to enable imaging ofsubcutaneous structures, such as a superficial vessel 50 seen in FIG.27, without providing undesired compressive forces thereon.

FIGS. 28A and 28B depict a probe cap 260 according to one embodiment,wherein the body of the cap defines a cavity 262 and a fixture 266 forreceiving thereon a needle guide. An ultrasonically transparent membrane268 is included proximate an aperture 280 at a distal end of the capbody to cover the transducer of the head of an ultrasound probe insertedtherein. An ultrasonically transmissive medium, such as ultrasound gel269, can be placed on an interior surface of the membrane 268 to ensureacoustic coupling between the transducer and the skin of the patient. Aswith other cap embodiments described herein the probe cap 260 can beconfigured as a sterile cap to provide sterility or isolation for theultrasound probe. Spacers 270 can also be included on either side of themembrane 268 to prevent compression by the cap 260 of superficialvessels when the cap 260 is placed against the skin. Note thatultrasound gel can also be placed between the membrane 268 and thepatient's skin to improve signal transfer, if desired.

FIGS. 29A-29D depict details of a probe cap assembly 310 according toanother embodiment, wherein the assembly includes a cap body defining acavity 312 for receiving therein the head 32 of the ultrasound probe 12,as before. Also as before, an engagement feature 314 is included tosecure the cap body to the probe 12.

The cap body is movable between two parallel rails 350 of a bracket 340.Each rail 350 includes a plurality of slots 352 that align withcorresponding slots on the opposing rail 350. Tabs 319 included oneither longitudinal end of the cap body are configured to be selectivelyreceived into corresponding opposed slots 352 of the rails 350, as shownin FIGS. 29A-29D. In the illustrated embodiment, the cap body isselectively repositionable along the bracket rails 350 via manualmovement by lifting the cap body so as to remove the tabs 319 from thecorresponding slots 352, repositioning the cap body as desired withrespect to the bracket rail slots, then inserting the tabs into theselected slots. In other embodiments, it is appreciated that othermodalities for moving the cap body relative to the bracket are possible,including sliding movement, gear-driven movement, etc.

As best seen in FIGS. 29B-29D, a needle guide 342 is included in thebracket to guide a needle into the patient's body when the probe capassembly 310 is placed on the patient's skin. An observation hole 346 isalso included on the bracket 340 so as to enable a clinician insertingthe needle to observe blood flashback upon the needle accessing thesubcutaneous vessel.

Note that the needle guide 342 in the present embodiment is disposed ata fixed angle with respect to the bracket 340 and that the cap body ismovable along the bracket with respect to the needle guide. Thisarrangement thus enables subcutaneous tissue to be imaged, by theultrasound probe disposed in the cap body, at differing discretedistances from the needle guide 342. Further, this arrangement enables aneedle inserted through the needle guide 342 to access an ultrasonicallyimaged vessel or other target at any one of a plurality of depths belowthe skin without the need for adjusting the angle of attack of theneedle.

In greater detail, the probe 12 while disposed in the cap body of theprobe cap assembly 310 can ultrasonically image a subcutaneous vesselwithin the patient and determine the depth below the skin surface atwhich the vessel resides. One or more of the slots 352 are marked with anumber, indicating the depth below the skin at which a needle insertedinto the patient through the needle guide 342 will intercept thesubcutaneous vessel. Thus, the bracket 340 can be adjusted until thetabs 319 thereof are disposed in the slots 352 on either rail 350corresponding to the depth of the imaged vessel. When the needle isinserted into the patient's skin through the needle guide 342, it can beadvanced until it intercepts and accesses the imaged vessel at thedetermined depth, as desired. As such, it is appreciated that the probecap assembly 310 can assist with needle access of an ultrasonicallyimaged vessel through a fixed-angle needle guide regardless of the depthof the vessel, thus obviating the need for an adjustable angle needleguide in the present embodiment. Note that the depth measurements of thebracket can vary from what is shown, but in one embodiment, the depthsaccessible via the probe cap assembly 310 vary from about 0.3 cm toabout 1.5 cm.

FIGS. 30A and 30B depict a probe cap 360 according to anotherembodiment, wherein the cap body defines a cavity 362 for receivingtherein the head 32 of the ultrasound probe 12 and an engagement feature364 to secure the cap body to the probe 12. A stabilization arm 365extends from the cap body so as to enable the cap 360 (and the probe 12received therein) to be secured to the patient via a band wrapped aroundthe stabilization arm and the arm of the patient, for instance.

As shown, the probe cap 360 further includes a deflector portion 390 fordeflecting an ultrasound signal both emanating from and travelling tothe transducer of the ultrasound probe 12. The deflector portion 390 isformed as part of the probe cap 360 and defines a channel 392 and anaperture 396 through which ultrasound signals can pass. The deflectorportion 390 further includes a deflecting surface 394 disposed in thechannel 392. In the present embodiment the deflecting surface 394 isdisposed at an angle of about 45 degrees with respect to the transducersurface of the probe head 32 so as to deflect ultrasound signalsemanating therefrom through an angle of about 90 degrees, though thedeflecting surface can be positioned in other embodiments at otherangles so as to produce different resulting angles of signal deflectionwith respect to the probe transducer.

FIG. 31 shows the probe cap 360 positioned against the skin 356 of apatient such that signals emanating from the transducer of the probehead 32 travel through the channel 392, are deflected by the deflectingsurface 394, and are directed downward into the body of the patient.Ultrasound signals reflected by an imaged target within the body andreceived into the channel 392 are also similarly deflected by thedeflecting surface 394 toward the probe head 32 for receipt by thetransducer. The deflecting surface 394 can include any suitable materialhaving a suitable density so as to reflect the ultrasonic signalstravelling through the channel 392. In one embodiment, the deflectingsurface includes a plastic material. Also, in one embodiment, thechannel 392 is at least partially filled with an ultrasonicallytransmissive medium, such as an ultrasound gel. In another embodiment, ahydrogel-based spacer component can be disposed in the channel 392, asin previous embodiments. In yet another embodiment, the deflectorportion can be integrated into the probe head itself, without thepresence of a probe cap. Use of the deflecting probe cap 360 enables theprobe 12 to be positioned parallel to the skin 36 of the patient, thuseliminating the need for the clinician to hold the probe upright duringuse.

FIG. 32 shows that the deflecting probe cap 360 in one embodiment can beincluded as part of an assembly similar to that shown in FIGS. 29A-29D,wherein the cap body is selectively movable between two rails 410 of abracket 400. The rails 410 each include corresponding slots 412 forreceipt of tabs 369 included on the cap body so as to position the probecap at one of a plurality of possible distances from a needle guide 402included on the bracket 400. As before, an observation hole 406 isincluded proximate the needle guide 402. As described further above inconnection with FIGS. 29A-29D, the assembly shown in FIG. 32 enablesvessels at a variety of subcutaneous depths to be ultrasonically imagedand accessed by a needle disposed in the fixed-angle needle guide 402 bymoving the bracket 400 with respect to the probe cap 360 such that theneedle intercepts the imaged vessel at the intended depth.

FIGS. 33A and 33B depict the deflecting probe cap 360 according to oneembodiment, wherein the deflector portion 390 is hingedly connected tothe remainder portion of the cap body via a hinge component 420,including a mechanical or living hinge for instance. So configured, thedeflector portion can be selectively positioned so as to deflectultrasound signals along a deflected signal path 424A (FIG. 33A), orrotated out of the ultrasound signal path (FIG. 33B) so as to enable theultrasound signals to travel along an undeflected signal path 424B. Alatch 426 or other suitable modality can be included to selectivelysecure the deflector portion 390 in place. Note that in one embodiment adeflecting probe cap can be adjustable such that deflection of theultrasound signal can be achieved through a variety of angles.

FIG. 34 shows a needle guide 450 according to one embodiment that can beemployed with one or more of the probe caps described herein, such asthe probe cap 460 shown in FIG. 35B, or can be attached directly to theultrasound probe. As shown, the needle guide 450 includes a curved,V-shaped open channel 454 that centers a needle therein yet enables theclinician to continuously adjust the angle of attack θ for the needle atthe insertion site during needle insertion, as shown in FIG. 35A. Notethat the shape of the channel can vary from what is shown and described.

Embodiments of the invention may be embodied in other specific formswithout departing from the spirit of the present disclosure. Thedescribed embodiments are to be considered in all respects only asillustrative, not restrictive. The scope of the embodiments is,therefore, indicated by the appended claims rather than by the foregoingdescription. All changes that come within the meaning and range ofequivalency of the claims are to be embraced within their scope.

What is claimed is:
 1. A cap for use with an ultrasound probe, comprising: a cap body defining a cavity into which a head portion of the ultrasound probe is removably received; a stabilization arm extending from a first side of the cap body for stabilizing the cap against a skin surface of a patient; and a needle guide associated with a second side of the cap body different from the first side thereof, wherein the needle guide is separate from the stabilization arm.
 2. The cap as defined in claim 1, wherein the stabilization arm further defines a hole to enable a clinician to contact the skin surface of the patient proximate a needle insertion area, a perimeter area proximate the hole being contoured.
 3. The cap as defined in claim 1, further including an engagement feature for securing the cap to the ultrasound probe, wherein the engagement feature is configured to couple with a corresponding engagement feature of the head portion of the ultrasound probe.
 4. The cap as defined in claim 1, wherein the needle guide is removably attachable to a fixture included on the cap body.
 5. The cap as defined in claim 1, wherein the needle guide includes a channel in which a portion of a needle can be movably received, the channel including an abutment surface upon which the needle can pivot within the channel so as to selectively alter an angle of attack of the needle with respect to the skin surface of the patient.
 6. The cap as defined in claim 1, wherein the stabilization arm extends from the cap body enabling the cap to be secured to the patient with a band or strap wrapped around the stabilization arm and the patient so as to support the ultrasound probe against the skin surface of the patient.
 7. The cap as defined in claim 1, wherein the stabilization arm has a tallest height that is less than half a height of the cap body.
 8. A cap assembly for use with an ultrasound probe, comprising: a cap body defining a cavity into which a head portion of the ultrasound probe is removably received, wherein the cap body includes a tab; and a bracket including a stationary needle guide, the cap body received in the bracket at a plurality of designated locations along a length thereof, the cap body movable with respect to the bracket in accordance with the plurality of designated locations so as to enable a distance between the needle guide and the cap body to be selectively varied, wherein each of the plurality of designated locations are configured to couple with the tab to secure a positioning of the cap body.
 9. The cap assembly as defined in claim 8, wherein the needle guide defines a fixed angle of attack for a needle disposed therein, and wherein selective variation of the distance between the needle guide and the cap body enables interception of a subcutaneous path of the needle with a desired subcutaneous target imaged by the ultrasound probe.
 10. The cap assembly as defined in claim 9, wherein the bracket includes demarcations indicating a depth of interception of the needle with the imaged subcutaneous target.
 11. The cap assembly as defined in claim 8, wherein the bracket includes first and second rails between which the cap body is movably disposed, the first and second rails including a plurality of aligned slots into which the tab disposed on the cap body can be removably received to position the cap body at a predetermined distance from the needle guide.
 12. The cap assembly as defined in claim 8, wherein the cap assembly is configured to direct ultrasound signals into a patient produced by the ultrasound probe when the cap assembly is placed against skin of the patient.
 13. The cap assembly as defined in claim 8, wherein the bracket further includes an observation hole proximate the needle guide for observing blood flashback from a needle. 